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Network anomaly detection (NAD) aims to capture potential abnormal behaviors by observing traffic data over a period of time. In this work, we propose a machine learning framework based on XGBoost and deep neural networks to classify normal traffic and anomalous traffic. Data-driven feature engineering and post-processing are further proposed to improve the performance of the models. The experiment results suggest the proposed model can achieve 94% for F1 measure in the macro average of five labels on real-world traffic data.

The quality grading of mangoes is a crucial task for mango growers as it vastly affects their profit. However, until today, this process still relies on laborious efforts of humans, who are prone to fatigue and errors. To remedy this, the paper approaches the grading task with various convolutional neural networks (CNN), a tried-and-tested deep learning technology in computer vision. The models involved include Mask R-CNN (for background removal), the numerous past winners of the ImageNet challenge, namely AlexNet, VGGs, and ResNets; and, a family of self-defined convolutional autoencoder-classifiers (ConvAE-Clfs) inspired by the claimed benefit of multi-task learning in classification tasks. Transfer learning is also adopted in this work via utilizing the ImageNet pretrained weights. Besides elaborating on the preprocessing techniques, training details, and the resulting performance, we go one step further to provide explainable insights into the model's working with the help of saliency maps and principal component analysis (PCA). These insights provide a succinct, meaningful glimpse into the intricate deep learning black box, fostering trust, and can also be presented to humans in real-world use cases for reviewing the grading results., Comment: Accepted to ICMLA 2020; 8 pages, 8 figures, 3 tables

We have demonstrated world-record thermophotovoltaic (TPV) conversion efficiency in two materials systems operating at two different thermal emitter temperatures. A GaAs-based PV device under a 2330 °C thermal emitter produced an efficiency of (31 ± 2)%, and an In 0.53 Ga 0.47 As -based PV device under a 1300 °C thermal emitter produced an efficiency of (30 ± 2)%. The electrical output power densities of the cells were 2.45 W/cm2 and 0.658 W/cm2, respectively. Critical to these high efficiencies were the cells' high reflectance of photon energies below the absorber band gap. Unlike solar PV, for which sub-band gap (SBG) light is lost, a TPV cell can reflect SBG light back to the thermal emitter where it can be recycled. The demonstrations were made on a custom-built measurement platform in which a ~ 100 cm2 graphite thermal emitter was heated under vacuum. The TPV efficiencies were evaluated by comparing the measured electrical output power of the cell with the total power absorbed by the cell. The measured TPV efficiencies as a function of thermal emitter temperature were corroborated by our full system modeling. As far as the authors are aware, these are the highest TPV conversion efficiencies ever measured, and device improvements should yield > 40% efficiency in the near future.

Mobile/multi-access edge computing (MEC) is therefore developed to support the upcoming AI-aware mobile services, which require low latency and intensive computation resources at the edge of the network. One of the most challenging issues in MEC is service provision with mobility consideration. It has been known that the offloading and migration decision need to be jointly handled to maximize the utility of networks within the latency constraints, which is challenging when users are in mobility. In this paper, we propose Mobility-Aware Deep Reinforcement Learning (M-DRL) framework for mobile service provision problems in the MEC system. M-DRL is composed of two parts: DRL specialized in supporting multiple users joint training, and glimpse, a seq2seq model customized for mobility prediction to predict a sequence of locations just like a “glimpse” of future. Through integrating the proposed DRL and glimpse mobility prediction model, the proposed M-DRL framework is optimized to handle the service provision problem in MEC with acceptable computation complexity and near-optimal performance.

Sentiment analysis has an important role in social media monitoring as it extracts public opinions, emotions, and feelings about certain products or services. There are several publications in building a system to identify opinions from text using rule-based approach, lexicon-based approach, or machine learning. In this paper, we propose and compare several deep learning models to solve sentiment analysis problem of the Internet Movie Database (IMDb) review sentiment dataset. The feature extractor consists of a convolutional layer, followed by a max pooling layer and a batch normalization layer. To solve the vanishing gradient problem, we use a residual connection to concatenate the input values with the extracted features before feeding the output into a recurrent layer. Our best model has an accuracy of 90.02%.

In the paper, a smart embedded microcomputer system will be constructed and will recognize objects within images streamed in real time. After the manipulator has been trained to move automatically, it will be equipped to control objects without a human operator under various environments. To achieve this aim, the image recognition system should be able to identify objects as well as humans. Specifically, it must undergo neural network training, learn the features of target objects, and measure the relative distances between the objects in a space to determine their respective locations and patterns of movement.

This paper is prepared to analyze the current application of augmented reality in industrial auxiliary maintenance, study the basic framework of connectivity, data integration model and human-machine interaction way, and explore the standardized methods. The standard verification platform is built from two aspects of system level and typical auxiliary maintenance scenarios. The established standard is tested and verified, and the iterative optimization of the standard is realized through test verification.

Lexicon-based sentiment analysis is a popular and practical approach for sentiment analysis. However, sentiment lexicons, which may be abundant in some language such as English, are scarce in many other languages. The cross-lingual lexicon learning aims to extend lexicons for the language with less resources from those lexicons available in other languages. In this paper, we propose an approach that builds a skip-gram variant to map word spaces across languages so as to construct lexicons for the language with less resources. We show in our preliminary experiment that our approach can generate lexicons that are similar to those crafted by human experts.

This paper presents the life period estimation of stamping process by analyzing its punch sounds with a deep neural network (DNN). Neuro-approximated MFCC (NA-MFCC) feature extraction has also been proposed to trade estimation accuracy for computation complexity at a finer granularity. Several Pareto-optimal configurations have been reported with the performance measured on an ARM Cortex A15-based prototype.

This study proposed an efficient hardware architecture design of Ensemble Empirical Mode Decomposition (EEMD) processor for the signal analysis of Electrocardiography (ECG). The proposed processor is implemented in an on-board Xilinx FPGA for on-line signal processing of the non-linear and non-stationary signal. The EEMD method is appropriate to analyze the non-linear ECG signal with assisting white noise and decompose the signal into 8 sets of Intrinsic Mode Functions (IMFs). The experimental result shows that the mode mixing problem, which exists in the Empirical Mode Decomposition (EMD) method, solved by the proposed EEMD processor. The study solves the obstacle of mode mixing and achieves high accuracy with data error < 4.7×10-5. This approach can effectively analyze the non-linear and non-stationary biomedical signal and facilitate cardiovascular diseases diagnosis and long-term monitoring.

This paper presents a new chaos-based medical image encryption algorithm using iterative permutation and substitution operation. To address the drawbacks encountered when using the invertible area-preserving chaotic maps, we introduce a pixel swapping-based image scrambling method with permutation keystream sequence generated from the logistic map. In the substitution stage, each keystream element is generated from a 1-D chaotic map selected from a group of three 1-D chaotic maps according to the value of the pixel previous to the one it applies to, making the keystream sequence dependent on plain-image. As a result, the robustness of the proposed algorithm against chosen-plaintext attack is ensured and the diffusion intensity is increased. The results of NPCR and UACI tests indicate that the proposed algorithm takes only two cipher rounds to achieve a desired diffusion effect. Moreover, each of the three 1-D chaotic maps is constructed by combining of two existing 1-D chaotic maps (seed maps). Compared with its corresponding seed maps, the compound map has larger chaotic ranges and more complex chaotic properties while remaining simplicity, making it a good candidate for constructing image ciphers with a sufficiently large key space and high computational efficiency. Our theoretical analysis and experimental results indicate that the proposed algorithm has a high level of security.

Nowadays, a large amount of image information is transmitting on the internet, and people are focusing more on image security. These years, encryption algorithm based on “scrambling-diffusion” architecture has made great achievement in security performance. Nevertheless, there is no need to encrypt the full image. Only part of it matters, which is defined as Region of Interested (ROI). In this paper, we propose a pixel-level image encryption method based on semantic segmentation. We use a PSPNet model trained on Cityscapes dataset to gain the coordinate of each pixels in ROI, then we encrypt these coordinates with a novel chaotic encryption system we proposed. In this system, we improved the scrambling-diffusion architecture. Scrambling and diffusion share the chaotic sequence iterated by the four-dimensional hyperchaotic Chen system, and generate the required key flows independently. Our encryption system acts well in the test, almost all the coordinates of ROI are covered. Cryptanalysis shows its superior security.

Cell gap thickness measurement on the scale of micrometers has been widely developed, due to its importance for applications such as display. In this paper, we propose and demonstrate a simple and precise method for measuring a millimeter-scaled cell gap by using a terahertz time-domain spectroscopy system. Basically, it is a kind of spectrum scanning method with a light source of broadband terahertz radiation. This method allows us to measure the cell gap from 15 $\mu\text{m}$ to 1.5 mm. In addition, the accuracy of measured thickness for the proposed method is also discussed and analyzed. This is the first time, to our best knowledge, that we can precisely measure the cell gap thickness as high as millimeters by optical measurement.

Multi-level morphological active contour algorithm (MMAC), was proposed in [3-4], to incorporate mathematical morphology for tree detection and crown delineation with the average prediction error around 4% in mountainous areas. However, two major drawbacks come with the design of MMAC algorithm, which are huge computational complexity and certain level of false alarm or omission rate. The paper provides a solution for two major problems by proposing a gradient vector flow (GVF) snake based MMAC algorithm. The GVF snake model took advantage of the gradient vector force of the LiDAR image and expand the boundary of each blob to approximate the real crown of each forest candidate. According to the experimental studies, the proposed algorithm could help improve the computational complexity and detection rate of the original MMAC algorithm effectively.

All-optical processing and generation are regarded as a key solution to achieve ultrahigh bitrate communication in next generation. Silicon based optical waveguides have been widely developed, including ultrafast electrical-optical modulator, splitter, wavelength generator, and etc. However, the carrier relaxation issues as well as inevitable two-photon absorption in communication regions limit its application in developing ultrafast all-optical modulation and supercontinuum generation. Recently, large optical bandgap materials have been utilized to demonstrate nonlinear waveguide applications for all-optical processing. Tantalum pentoxide (Ta 2 O 5 ) used to serve as gate dielectric and optical coatings in optoelectronic devices due to its high dielectric constant and refractive index properties. Nowadays, Ta 2 O 5 with high optical nonlinearity and free of nonlinear absorption let it suitable in developing small footprint, high power operation optical devices [1, 2].

Nonlinear wavelength generations by using the optical waveguides are more compact, low cost, and efficient than using the traditional solid state systems [1], and the generated broadband light sources can be utilized in optical coherence tomography, frequency metrology, optical communications, and many other. In this work, the high quality of tantalum pentoxide (Ta 2 O 5 ) micro-ring resonator has been fabricated to realize the low power parametric frequency conversion in the communication region. Figure 1 shows the illustration and scanning electron microscope (SEM) image of Ta 2 O 5 based micro-ring resonator. The width/height of the ring waveguides is set as 1.5μm/0.7μm for the anomalous dispersion, which is a key element to minimize the phase mismatch in the parametric frequency conversion process. By fitting the transmission spectrum of the Ta2O5 ring resonator, the load quality factor is ∼50000 and the loss coefficient is ∼0.5cm−1. The unload quality factor is estimated to be ∼180000, which is the best record of Ta 2 O 5 based micro-ring resonator [2].

Rising with consumer electronics, mobile and wearable devices electronic packaging is developed with high power, high I/O, small size and good reliability performance. Among the various packages adopted by industry, Wafer Level Chip Size Packaging (WLCSP) and Ball Grid Array (BGA) possess characteristics mentioned above and therefore widely used in various kinds of devices. However, concerning different environments it will encounter, electrical packaging needs stronger reliability to address strict situations that maid damage and shorten device's life time which is mostly due to the failure of packaging's solder joint serving as an I/O of chip to function itself or communicate with others. As stated in many literatures, the electrical packaging's solder bump could been damaged due to the stress and strain induced by mismatch of coefficient of thermal expansion (CTE) between chip and substrate under thermal loading or Temperature Cycling Test(TCT), which is one of the reliability test that is required before reaching the market. Besides ameliorating the material employed on packaging, electrical packaging is also in need of good structural design to acquire a packaging form that can be able to possess better reliability performance and longer cycling life to be more durable. Taking into consideration that assessing electrical reliability is generally time and fund consuming, simulation can be a decent alternative if it is able to analyze electrical packaging accurately via finite element method. In addition, simulation benefits companies much shorter time in research, allowing product to be more competitive when it is able to enter market with a shorter research and development period. In recent years, the loading of TCT is set to be harsher, failing the test specimens at a faster pace to reduce reliability test time. According to JEDEC standard, regular test temperature ranges from −40°C to 125°C is adopted in this research. During the session of accelerated temperature cycling test, temperature often exceeds one third of solder's melting temperature, triggering the creep behavior to be more obvious and considerable as the creep strain is accumulated to be an amount that is not ignorable. With respect to finite element algorithm, element size used in finite element method can significantly interferes simulation result. It causes considerable deviation of packaging life prediction between larger and smaller element when they are applied on TCT simulation. As a result, finding the suitable element size to various kinds of packaging is essential when the accurate simulation result is required to access or develop a packaging. In summary, the purpose of this research is finding the appropriate element size matching with experimental cycling life by comparing the response of several WLCSP sustaining to the loading of accelerated temperature cycling test. All simulations are conduct with Anand and modified Anand.

Forests in mountainous areas normally contain a diverse variety, including tropical rain forests, subtropical evergreen forests, temperate forests, and alpine cold forests. These forests distribute vertically along the central region and can be categorized into broadleaved, mixed, and conifer forests. Terrain features in mountainous areas make manual inspection of forests both labor-intensive and time-consuming if not impossible. By utilizing remote sensing techniques the efforts of field sampling could be effectively reduced.

The nonstoichiometric ITO/n-SiC/i-SiC/p-Si/Al light-emitting diodes (LEDs) with dense Si quantum dots (Si-QDs) embedded in the Si-rich SixC1-x -based i-SiC layer are demonstrated. The Si-rich SixC1-x films with buried Si-QDs are grown by the plasma-enhanced chemical vapor deposition with varying substrate temperatures. After the annealing process, the average Si-QD size in the Si-rich Si0.52C0.48 film is 2.7 ± 0.4 nm with a corresponding volume density of 1.43 × 1018 cm-3. By increasing the deposition temperatures from 300°C to 650°C, the turn-on voltage and turn-on current of the ITO/n-SiC/i-SiC/p-Si/Al LEDs are found to decrease from 13 to 4.2 V and from 0.63 to 0.34 mA, respectively. In addition, these Si-rich SixC1-x LEDs provide the maximal electroluminescent (EL) power intensity increasing from 1.1 to 4.5 μW/cm2. The yellow (at 570 nm) EL emission power of the ITO/n-SiC/i-SiC/p-Si/Al LEDs reveals a saturated phenomenon due to the Auger effect. The dissipated energy by the lattice thermal vibration contributes to a decayed EL emission power at higher biased currents. The corresponding power-current slope is observed to enhance from 0.45 to 0.61 μW/A with the substrate temperature increasing to 650°C.

The crack-free and low surface roughness of Ta 2 O 5 film has been deposited by magnetron sputtering technique. The propagation loss of 1.5 dB/cm with the total coupling loss of 3.2 dB for the Ta 2 O 5 based channel waveguide with inverse taper structure has been successfully demonstrated.

Travel activities have been widely applied to quantify spatial interactions between places, regions and nations. In this paper, we model the spatial connectivities between 652 Traffic Analysis Zones (TAZs) in Beijing by a taxi OD dataset. First, we unveil the gravitational structure of intra-urban spatial connectivities of Beijing. On overall, the inter-TAZ interactions are well governed by the Gravity Model $G_{ij} = {\lambda}p_{i}p_{j}/d_{ij}$, where $p_{i}$, $p_{j}$ are degrees of TAZ $i$, $j$ and $d_{ij}$ the distance between them, with a goodness-of-fit around 0.8. Second, the network based analysis well reveals the polycentric form of Beijing. Last, we detect the semantics of inter-TAZ connectivities based on their spatiotemporal patterns. We further find that inter-TAZ connections deviating from the Gravity Model can be well explained by link semantics., Comment: 6 pages, 4 figures

Nonstoichiometric Si 1−x Ge x films fabricated by plasma enhanced chemical vapor deposition (PECVD) with different flounce ratios are demonstrated to show the composition ratio dependent optical properties, including refractive index, bandgap and optical absorption. By increasing the fluence ratio from 0.2 to 0.5, the refractive index of Si 1−x Ge x film raises from 3.527 to 3.927, with the absorption coefficient enlarging from <

This paper studies the terminal sliding mode control (TSMC) issue considering the fault-tolerant design. In the proposed scheme, TSMC can keep the merits of conventional sliding mode control (SMC), including robustness to uncertainties and/or disturbances, fast response, and easy implementation. Moreover, by using TSMC, the system states of TSMC will converge in finite time to the control objective point, i.e., equivalent point, after the systems states intersect the sliding surface. Simulation results show the advantages of the proposed method.

A 4-nm large Si-QD doped SiOx rib waveguide based optical absorption modulator with free-carrier density dependent relaxation lifetime is demonstrated. The switching response is shortened to 9 μs by reducing pumping duty-cycle to 0.5 μs.

Distributed metadata management is an efficient way to address the huge data of mineral information resources, which are usually distributed stored. In this paper, existing related metadata standards of mineral resource are firstly explored, based on which three typical kinds of metadata management mode, centralized metadata management mode, distributed metadata management mode and shared metadata management mode are summarized and evaluated. Considering the advantages and disadvantages of the three modes and the features of management, a framework for distributed metadata management of mineral information resources with access control is proposed to provide data management and share ability with access control. In this framework, a mineral information metadata table based on the standard published by China Geological Survey is defined to describe the metadata of distributed mineral information resources. The framework provides metadata and catalogue management abilities to fulfill data share and access control between different departments. The detailed design of the management framework is also given in this paper.

In recent years, the importance of virtual terrain visualization technology for the digital earth models has been more obvious. Since two-dimensional (2D)vector data still occupy the vast majority of the GIS (Geographic Information System) vector data, the algorithm for vector data rendering in virtual terrain visualization plays a crucial role in the digital earth models. After deeply analyzing the current algorithms, the paper proposes an improved vector data rendering algorithm based on texture. As for the problem of aliasing artifacts, according to the context of rendering scene (e.g. the viewpoint's position), the improved algorithmutilizes the method of the dramatic texture overlay, combining the visualization of the terrain with the vector data selected by the view scene using the method of Render-to-Texture based on DirectX in real-time. And meanwhile the method constructs the mapping table between the vector data and texture to simplify the operation for the highlight selecting and the vector data's querying. After applied in the practical vector data, the improved algorithm is proved that it not only keeps the same advantage as the texture-based method such as fast rendering and easy to control the layer, but also is notconfined by the resolution of the texture without the phenomenon of aliasing artifacts and raises the efficiency in highlight selecting and the vector data attributes' querying.

Recently, three dimensional integration circuits technology has received much attention because of the demands of gradually increasing functionality and performance in microelectronic packaging for different types of electronic devices. For 3D chip stacking, high density interconnections are required in high-performance electronic products. Though the bumping process used could be either electroplating or electroless plating for fine pitch solder micro bumps, its process effect on the reliability performances of micro joints still needs to be clarified from the microstructural point of view, especially for the fine pitch solder micro bump interconnections. In this study, we discussed the effect of Ni/Au metal finishing fabricated by electro- and electroless plating on the reliability properties of 30μm-pitch lead-free solder micro interconnections. Palladium layer was chosen to evaluate its influence on the reliability response of fine-pitch solder micro joints with electroless Ni/Au surface finishing. The chip-to-chip test vehicle having more than 3000 solder micro bumps with a bump pitch of 30μm was used in this study. Two types of metal finishing, electroplating Ni/Au and electroless plating Ni/Pd/Au, were chosen and fabricated on the silicon carrier. In silicon carrier, the thickness of Ni layer was 2~3 μm while that of electroplating and electroless plating Au layer was 0.5μm and 0.02μm respectively. The thickness of Pd layer within the electroless Ni/Pd/Au structure was 0.05~0.1μm. The silicon chip with a solder micro bump structure of Cu/Ni/SnAg having a thickness of 5μm/3μm/5μm was used for C2C bonding. We adopted the fluxless thermocompression process for both types of micro joints and then the chip stack was assembled by capillary-type underfill. Temperature cycling test (TCT) and electromigration test (EM) were conducted to assess the effect of metal finishing on the reliability properties of those solder micro bump interconnections. The reliability results revealed that the thickness of Au layer would apparently influence the microstructure evolution within the solder micro bump interconnection after bonding process though the micro joints with thick Au layer could pass the 1000 cycles TCT. The micro joints with complicated interface reaction resulted from the thicker Au layer might lead a negative effect on the long-term reliability properties while the Pd layer would enhance the wetting ability of solder micro bump during joining. The results of EM reliability test displayed that both types of the micro joints had excellent electromigration resistance under the testing condition of 0.08A/150°C. The activated IMC growth within the micro joint during EM testing was the major reason for this superior property. This investigated completely presented the effect of metal finishing by electro- and electroless bumping processes on the reliability properties of fine pitch solder micro bump joints.

This work presents a high voltage operational amplifier (HVOPA) and a high voltage transceiver (HVT) for Battery Management Systems (BMS). Battery Interconnect Modules (BIM) in BMS must be able to accommodate input voltage up to tens of volts, perhaps even hundreds of volts, which is difficult to be realized using a logic-based process. To realize a possible solution on silicon, BIM shall be fabricated using HV semiconductor processes, which usually are constrained by the voltage drop limitation between gate and source of HV devices. To overcome such a limitation, a HVOPA and a HVT are proposed in this work to carry out high voltage analog circuit design and data transmission. An experimental prototype is implemented using a typical 0.25 μm 1-poly 3-metal 60V BCD process. The post-layout-extracted simulation results proved the functional correctness of our proposed design.

In order to meet the demands of high-performance, high-speed, small form factor and multi-function integration in portable electronic products, the development of packaging technology now trends toward system-in-package (SiP) technology. Three-dimension (3D) integrated circuit technology provides a way to integrate complex micro systems through vertical interconnections among individual devices/chips. For the multi-chip stacking with fine gap and fine pitch solder micro bump interconnection, the dispensing of capillary underfill presents a major limitation in term of process time and process ability during assembly process. In this study, for realizing the multi-chip stacking, we developed a simplified assembly process by wafer-level underfill (WLUF). The WLUF film was laminated on 8” chip wafer with a thickness of 50µm. The chosen solder micro bump structure was Cu/Ni/Sn2.5Ag with a pitch of 30µm. After wafer dicing, the chip with WLUF was assembled on the substrate chip having the same micro bump structure. The optimized bonding parameters in such assembly process were also determined. The experimental results revealed that a robust joining and no voids formed between bonding interface could be achieved by this simplified assembly process. The results of reliability test showed that all samples could pass LV-3 pre-condition test. The failure percentage was about 10% under 1000 cycles of TCT where the failure mode was the cracks of micro joints and Al pad. The failure percentage was about 52% under 1000 hours of THST where the failure mode was crack of micro joints. All samples could pass the Un-biased HAST test. We also evaluated the feasibility of multi-thin-chip stacking by WLUF film. The experimental results showed that the first-layer micro joints raised 2% increase in contact resistance and the thickness of IMC layer increased 1µm thick only after four-layer chip stacking process. These experimental results displayed that the WLUF material exhibited a highly applied potential for multi-chip assembly process.

The reason why university teachers loyal to the organization, stay in it and work hard have a wide range of psychological motivation, which is known as organizational commitment. Through investigation of 430 teachers from 18 universities in Beijing, Tianjin and Hebei province, we found that the organizational commitment of university teachers included four dimensions as ideal commitment, affective commitment, normative commitment and continuance commitment. Moreover, the professional title, academic qualification, graduate college and the children status was found to have significant influence on organizational commitment. Finally, we discussed the empirical result and gave some suggestions to the managers. The research result will establish the foundation of deep research for university teachers' organizational commitment and provide reference to university managers in personnel decision making.

Directly modulated distributed feedback (DFB) lasers operating around 1550 nm has been demonstrated. The reversed ridge waveguide (RWG) and high-speed planarized coplanar waveguide (CPW) line are used for electron confinement and reducing resistance and capacitance of device. −3 dB bandwidth of > 20 GHz with 25 Gb/s data transmission was successfully achieved.

A Si quantum dot enhanced electroluminescence at 580 nm from the Si-rich Si x C 1−x p-i-n LED grown by PECVD at silane-rich condition is demonstrated with a power-current slope of 0.2 μW/A at bias of 8.8 V.

In various geological applications of remote sensing, large amounts of data processing and mapping are demanded and there are inevitable problems such as managing data in different databases and working across different operating systems. Cross-platform GIS is an effective strategy for solving such problems. Based on the ideas of cross-platform software porting and module integration, this paper firstly proposes a hierarchical and component-based GIS framework for geological applications of remote sensing, then analyzes different implementation technologies, and, finally develops a specific prototype to verify the feasibility of the proposed framework.

Three-dimension geological simulation engine is the key to geological environment simulation which can visually support geological resource exploration and analysis. Design of a three-dimension geological simulation engine is presented in this paper firstly. The engine is then fully implemented and applied in a case study in the southern margin of Yili basin to verify its feasibility. In the case study, the proposed three-dimension geological simulation engine is proven able to efficiently support specific research on sandstone-type uranium deposits, in which the surface and underground geological environment simulated, the interlayer oxidation zone front ascertained, and the information of strata and metallogenic favorability extracted.

This paper focuses on the observation of lock time of a phase-lock loop (PLL) by software for a microcontroller both with and without disturbance by radio frequency interference (RFI). The perturbation method chosen in this paper is near-field injection (NFI) through a dedicated probe. The distributions of these clock counts (CC) with and without RFI are different. The result presents that PLL is sensitive to RFI and suitable for RFIs detection.

With the increased demand of functionality in electronic device, three dimensional integration circuits technology together with downscaling of interconnection pitch present an important role for the development of next generation electronics. In the current types of interconnects, solder micro bumps have received much attention due to its low cost in material and process. For fine pitch solder micro bump interconnections, selection of under bump metallurgical material is a crucial issue because the UBM structure/material will show a significant influence on the reliability performances of the solder micro bump joints. However, which UBM structure/material for fine pitch solder micro bump joint presents the better reliability properties is not concluded yet until now. In this study, the effect of UBM structural/material on the reliability properties of lead-free solder micro interconnections with a pitch of 30μm was discussed. The chip-on-chip test vehicle with solder micro bump interconnections having a diameter of 18 μm was adopted to evaluate the effects of UBM structure/material. There were more than 3000 micro bumps with Sn2.5Ag solder material on both the silicon chip and carrier. In this study, three types of UBM were selected on the silicon carrier: they were single copper layer with a thickness of 8μm; the Cu/Ni layer with the thickness of 5μm/3μm and the Cu/Ni/Au layer with the thickness of 5μm/3μm/0.5μm. The UBM was electro-plated on the Al trace and then the Sn2.5Ag solder with a thickness of 5 μm was deposited. For the silicon carrier with the bump structure of Cu/Sn and Cu/Ni/Sn, the silicon test chip with solder micro bump of Cu/Sn was used for chip bonding. The test chip having the solder micro bump of Cu/Sn and Cu//Ni/Sn was used for bonding with the silicon carrier having the Cu/Ni/Au UBM. In chip stacking process, we adopted the fluxless thermocompression process for each type of micro joints. After chip bonding process, the fine gap between bonded chips was filled by capillary type of underfill. The influence of underfill on the reliability of solder micro bump interconnects with various combinations of UBM structures were estimated also. After the assembly process, temperature cycling test (TCT), high temperature storage (HTS) and electromigration test (EM) were performed on the chip-stacking module to assess the effect of UBM structure/material on the reliability of solder micro bump interconnections. The results of reliability test revealed that only Cu/Sn/Au/Ni/Cu micro joint could not pass the TCT and HTS of 1000 cycles. After reliability test, the Cu/Sn/Cu joints showed the evidently microstructural evolution while the Cu/Ni/Sn/Cu joints did not show apparent microstructure change among all the types of micro joints and still revealed the most contents of residual solder within the joint. On the other hand, the existence of Au layer upon the UBM caused the complicated interface reaction between solder and UBM, which presented a negative effect during long-term reliability performance. The reliability results also displayed that the introduction of underfill could apparently enhance the reliability of micro joint under mechanical evaluation. From the results of EM reliability test, all the types of the micro joints showed excellent electromigration resistance under current stress of 0.08A at an ambient temperature of 150°C irrespective of the types of UBM. This superior property was attributed to the microstructure change transformed from the solder joint to the IMC joint within the solder micro bump interconnections during electromigration test. All the results of reliability test illustrated that the selection of UBM structure/material well influenced the reliability performance of fine-pitch solder micro bump interconnections in 3D chip stacking.

In this paper, a W-band four-way power divider/ combiner using waveguide rat-race hybrid and double-probe waveguide-to-microstrip transition is proposed. This divider/ combiner has properties of low loss, equal power splitting, compact structure, good return loss, and good heat dissipation. The 3D EM simulation results show that, from 90GHz to 100GHz, the return loss is better than 20dB and the insertion loss is less than 0.3 dB. Integrated with MMIC power amplifiers, the divider/combiner can be used in power combing systems to obtain solid-state high power with a high efficiency in W-band.

Recommender system has become an important research topic since the high interest of academia and industry. As a branch of recommender systems, collaborative filtering (CF) systems take its roots from sharing opinions with others and have been shown to be very effective for generating high quality recommendations. However, CF often confronts a problem of sparsity which is caused by relevantly less number of ratings against the unknowns that need to be predicted. In this paper, we consider a hybrid approach which combines the content-based approach with collaborative filtering under a unified model called Co-Clustering with Augmented data Matrix (CCAM). CCAM is based on information-theoretic co-clustering but further considers augmented data matrix like user profile and item description. By presenting results on a better error of prediction, we show that our algorithm is more effective in addressing sparsity through optimizing the co-cluster in mutual information loss between multiple tabular data than algorithm with single data and algorithms do not consider mutual information loss or co-clustering in our prediction framework.

Background modeling is one of the key techniques in video surveillance system. When the training images contain more moving objects or its number is not sufficient, the existing methods normally end up with incorrect background estimates. In this paper, we study a type of method on data analysis, i.e., Robust Principle Component Analysis (RPCA), and present its application on the background modeling. Unlike previous approaches based on statistics, the new method uses an advanced convex optimization technique that is theoretically guaranteed to be robust to large errors. Experimental results demonstrate that the proposed solution can robustly estimate the background from relatively few training images, even in the case of sudden change of lighting.

The purpose of this study is to understand how student behave in the online learning environment Moodle. By using Grey relational analysis to understand and to predict students' grades, researchers are interested in understanding if there is any association between students' interactivities and their final grades in Moodle system. We developed online materials for two-semester elementary calculus for the first-year students in college of management of a general University in Taiwan. The current data are collected from the online activities of the first semester, whose topics cover the introductory review through derivatives of exponential and logarithmic functions. Twelve online quizzes are built up to include all important topics of the coverage. GRA results are obtained from this group, so we can understand which online quiz activity is significantly correlated with students' final grades.

Aiming at the problem that the efficiency of mass vector data rendering in global 3D GIS is low, this paper put forward a new way of processing and scheduling the data. The problem of crack phenomenon after the compression of public boundary in LOD model of vector data have been solved by the way based on the Douglas-Pecuker algorithm. In addition, we add viewpoint height factor, improving the efficiency of rendering and displaying vector data, which we can get proof in experiments.

The DBD (Dielectric Barrier Discharge) is well known for its great advantages in various kinds of industrial applications and has been widely used in manufacturing process including flat panel displays, thin films and semiconductor packaging. There has been enormous progress on DBD source development and diagnostics to suit these different purposes. At the same time, there are increasing needs for moderate and efficient remote plasma sources in order to avoid electrical damage from microarcs or high energy ion collisions. To this end, a stable remote plasma using an extended DBD source having a stable effective discharge area of 550mm × 40mm was investigated. The electron temperature was measured from a Boltzmann plot based a PLTE (Partial Local Thermodynamic Equilibrium) model and electron density measured from linewidth broadening of H β line, with hydrogen insertion for comparison of the direct discharge region in between electrodes and the remote plasma region. The capacitance of DBD electrode as well as discharge energy and discharge power has been investigated with V-Q Lissajous analysis. Surface treatment of glass and polypropylene with various applied voltage and gas flow rates were studied. Combining optical and electrical diagnostics and surface analysis results on treated samples, the atmospheric plasma source for in-line processing was characterized.

The Center for Plasma-Material Interactions (CPMI) at the University of Illinois at Urbana-Champaign has developed a greater than 10 mm diameter 2.45 GHz microwave-induced atmospheric pressure plasma torch (APPT) for use in various manufacturing applications. The APPT has the ability to generate various atmospheric pressure plasmas (helium, argon, nitrogen) with a gas temperature range from room temperature (30°C) to more than 3,000 °C at the ignition area. The diagnostics of the electron temperature T e , electron density n e , and the plasma gas temperature T g are based on the optical emission spectroscopy (OES) technique. The detailed dependence of the T e , n e and T g on the microwave power, radial distance referred to the ignition point, gas type and gas flow rate will be presented individually. The validity of the OES technique, including the local thermal equilibrium conditions and the model for H β calculation, has been verified and analyzed by the OES measured results. OES results has shown that T e is in the range of 0.5–1.5 eV, n e is in the range of 1014-1016 cm−3 and T g is in the range of 900–3000 K by varying the power from 200–3000 W, depending on the type and the mixture ratio of the plasma gases. The spatial dependence of T e , n e and T g has shown a drastic decrease in T g but relatively slower changes in T e and n e . This provides possibility on both thermal and non-thermal operation conditions for applications of selectable material processes.